Extensive use of asbestos for thermal insulation and reinforcement of polymers such as in floor tiles and roofing shingles occurred during the first two thirds of the twentieth century. That practice ceased when it was found that asbestos fiber was considered to be carcinogenic. In fact, there is great concern that previously installed asbestos products within buildings may shed sufficient asbestos fiber to cause cancer to the building's inhabitants. Therefore, the Federal and subsequently State governments enacted legislation stipulating the procedures to be used for such removal to prevent the inadvertent diffusion of asbestos fiber throughout a building.
Asbestos removal in a building requires the physical isolation of the area in which such work is accomplished. In addition, such isolated areas must be maintained with negative air pressure so that any inadvertent release of asbestos fiber will remain in the isolated area to be filtered and collected for later safe disposal.
The area isolation method stipulated by most states requires the installation of two layers of either four or six mil polyethylene sheeting on each wall. Such sheets of polyethylene are very slippery and difficult to handle. Each of these layers must be sealed at the wall interfaces of the ceiling and floor. Ideally the sheets of polyethylene will extend around all of the walls of the isolation area to be joined at a single overlapping seam. When asbestos is removed from a ceiling or ceiling fixtures the floor must be covered with two layers of six mil polyethylene sheeting which extends up a wall and is sealed at the wall floor interface. Each layer or sheet is individually taped to the wall. In such instance the sheeting installed on the wall is applied after the installation of the floor sheeting.
As can be envisioned, the installation of such two individual layers of slippery sheeting continuously around an enclosed area utilizing nailed on furring strips or spray on adhesive requires several workers working in concert and as such is very labor intensive and frustrating for the installers; in many instances requiring reinstallation when it is found that the isolation is not complete.
The art of the instant invention utilizes special hangers which can conveniently be non-destructively installed around the walls of an area to be isolated on the wall at the ceiling and wall interface. Polyethylene sheeting of sufficient width to extend to the floor is then hung on the hangers. Flexible pressure sensitive tape is then applied to the top edge of the sheet to bond it to the wall/ceiling. Subsequently, the bottom edge of the polyethylene sheet is adhered in like manner to the wall at the wall/floor interface. The second layer of polyethylene sheeting is installed in like manner. The second sheeting layer being somewhat narrower in width so as to permit the pressure sensitive tape to be applied to the first previously installed layer of tape at both the floor and ceiling interfaces.